Sunday, June 17, 2007

Past the pins.

And honestly, these are some of the best photos yet. Secret? Tripod. 28 photos.

Partial detail strip and explanation, CZ75

By the way, DO NOT ATTEMPT WITH DECOCKING MODELS. If I recall correctly, they're put together on a jig at the factory. You don't have the jig, and neither do I.

We start where we left off: one CZ75B Compact .40S&W, field stripped, grips off.


The first thing to do is remove the mainspring, which you do by removing this pin. This pin is held in only by spring tension: you'll notice the mainspring "plug" sticks out a little at the bottom. Press that against a hard surface and the retaining pin will almost fall out by itself. In fact, with use it may very well do so.


And there you have it.


Simply pull the mainspring free. Some brake springs won't allow this until they are also removed.


Now remove the magazine brake spring. This pin retains it, and may need to be pressed free. These pins are retained partially by the grips so a loose fit is alright.


The mag brake and it's pin.


Here is a closeup of the fire control parts. You may refer back to this for a closer view of the parts I'm referring to in the next few sections.


Pointed out is the longer leg of the sear spring. It's function is to retain the safety, along with:


The safety detent plunger. CZ saw fit to leave the top accessible with a fork so you can pull it back with a small pin or screwdriver.


With the spring leg lifted out of the notch and the plunger pulled back, the safety slides right out. The fire control insert is now free of the frame and is shown in the middle.


This is a closer view of the double action leg and trigger bar, and clearer views of the safety retention devices.


Pointed out, the retaining tab for the right hand safety.


The tab simply lifts out of it's groove. To remove and insert the right side safety you must also press down on the trigger bar.


The small coil spring is the tensioner for the safety detent plunger. The plunger will simply press out to the inside of the frame.


The safety detent plunger.


The spring for the safety detent holds down the retaining pin for the hammer pin. It's free floating, just turn the frame over and it falls out.


This frees the hammer pin. This pin is also loose fit, and can simply fall out.


Pictured, the hammer, hammer pin, and retaining pin. On the left of the hammer body is the double action arm, on the bottom is the mainspring strut.


Pointed out here are the surfaces on the trigger bar that make the pistol work. The inside, lower surface presses against the double action arm, and the outer surfaces interact with the fire control insert for single action mode and for the firing pin safety.


Now let's take a look at the fire control insert. At the top (forward) you can see the ejector. The tab towards the bottom is the firing pin safety lever, it lifts under trigger pressure and presses the firing pin plunger up to free the pin.


A view of the bottom, with flash fill. The two underhanging tabs are the key to operation: (left is forward)


This tab is on the sear. When the trigger bar presses it the sear surface lifts off the hammer.


This tab is on the firing pin safety lever.


This is the sear surface.


There is one pin in the fire control insert, it holds everything together. You'll want to use somethign as a slave pin in order to get everything apart under control.


From right, clockwise: Insert body, sear, firing pin safety lever, FPSL spring, insert pin, sear spring


There you have it. That's as far as I'm currently capable of going since the trigger pin is severely staked and would need a replacement that I don't have, were I to remove it.


The operating table.


Assembly is the reverse of disassembly.

There you have it. I won't get to the CZ52 this weekend, I want to do some studying first. But, it will be done... it was my second gun, naturally it's next in series.

10 Comments:

Anonymous Standard Mischief said...

Teh awesome. This is the type of content that's perfect for a firearms wiki. Detailed, informative, and wholly outside the scope of Wikipedia (of which it makes no sense at all to compete with).

10:03 PM  
Anonymous TD said...

Excellent stuff. I'm glad I egged you on :-)

11:42 PM  
Blogger Tam said...

Ooh! Nice macros!

3:28 PM  
Blogger Dr. StrangeGun said...

....macro?

9:08 AM  
Blogger Tam said...

You did use the macro setting on the camera, yes?

9:15 AM  
Blogger Dr. StrangeGun said...

*smack forehead* indeed they are.

Somehow "macro" got associated in my head with those silly cat photos.

I can has brain fart.

10:07 AM  
Blogger Don Gwinn said...

Very cool.
Now just sit back and wait for the inevitable email from a guy with a box of CZ parts who can't get them back together.

8:50 AM  
Blogger Les Jones said...

Coolness.

If you don't know this trick already, here it is. When shooting from a tripod you can get steadier shots if you use a remote shutter release - the little cable that connects to the shutter release button.

If you don't have one or your camera doesn't accept one, a cheap and effective substitute is to use the camera's self-timer feature. Frame and focus the shot, go to the self-timer, press, and wait the five or ten seconds for the camera to shoot. That eliminates the little bit of vibration from your finger pressing the button.

1:19 PM  
Anonymous Anonymous said...

Great work! Can you show how to remove the pins from the hammer and strut?

9:51 AM  
Blogger 123 123 said...

This comment has been removed by a blog administrator.

10:51 AM  

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